560 ti SLI issues

[KingNosser]

I have had a single card for a long time but this week picked up another.

Installed today did a fresh driver install card was picked up and SLI enabled without an issue.

My problem is when I ran the cards at load the system would just reboot after a short time no error or pop up when loging back into windows.

Didn't feel like a card issue as normally the driver error would pop up.

I have a modular 750 watt PSU thought this might be the cause of the issue, but the way the machine would just restart felt more like a CPU OC issue. So I downclocked the CPU from 4.5Ghz @1.35v to 4.0Ghz @1.3v and have since made it past two runs of 3Dmark 11 score of 8500.

So my main question is: is this a PSU issue or an OC issue.

I'm not so concerned about losing some of my overclock if that is the cause of the problem, more concerned if it's the PSU being pushed too hard I'd have thought 750watts 52Amps was enough.

please respond with anything you feel may help me, I do hope I haven't just brought my planned upgrade on my card only to need a new PSU I just want stability without worry.

 

[SuB]

What brand is the PSU fella?

 

[KingNosser]

it's not a great brand Artic 750watt, after some further testing it's definately the PSU it just doesn't have enough power going to the cards when they are at load.

I tried several things and means I'd not normally take and they crash under load I guess I was lucky to have it pass a few times, but in heavier apps they just weren't getting enough juice.

for now I've disabled SLI and I'll look into getting a much better brand like a 850 watt corsair 80+ look into the 65 amps area and hope it's enough, it sucks to see that even the 8500 3dmarks could be better I feel cause I'd not even overclocked the cards it's lacking but in time it'll work out nice.

SFIV AE benchmark was over in a flash hardly 5 seconds and it had finished good fps in lots of games but stability like that would drive me crazy so up the power supply and it'll run much better, I tried the new card on it's own and it was fine no issue at all so it's PSU for sure.

Thanks for replying now off to look into a better PSU knew I should have got a much better one but at the time when building my PC it was all I could shell out at the time

 

[SuB]

no probs give us an update once you get a new PSU

 

[barnsley]

I'd personally recommend the RM750. Its quite cheap for what it is, is incredibly well built and it is modular. win,win,win!

 

[KingNosser]

850 I feel would be a bit better with a good brand since I overclock and have a fair few other items in the case so a little more wont hurt but I'll look into prices and check amps ratings and such, fully modular this time round and a modern corsair no skimping like last time.

Edit:

I had a look around online at prices and specs and such, used an total overkill PSU calculator and added everything up and it was min of 650 watt needed at 100% total load on all devices 725 watt, given that corsair is a good make when it comes to PSU's I'm seriously looking at the RM750 it's a fair bit cheaper than the RM850 and should do whats needed 80+ gold and modular as said so yep could well be getting that soon, unless I have the bit extra to go RM850.

shame it'll be about two more weeks until I've paid my bills and have enough spare to get it but first world problems two weeks isn't a long wait and it'll be worth it in the end.

Edit2:

In the end I went with the XFX Pro 850 watt core edition, I'll need to be tidy with cables but I have the time, I read some reviews and for the price it performs well and has 70amps on a single 12v rail and actually provides nearly all of the wattage. I decided to go with the XFX since it's manufactured by seasonic, heard some cases of fan issues and clicking on the Corsair GS800 and some bad reviews of the RM750/850 not being upto Corsairs normal build quality Idk if they hold any truth but it puts me off as a buyer. So I went with the XFX it was only £80 and if I'd have wanted fully modular it would have cost £110 didn't feel worth the extra and when comparing it to other PSU's I've mentioned it was a similar story but the main thing was the 70amps that swayed me.

I'll post again once I've installed and done a ton of benchmarks and such and let you know my thoughts on it.

 

[KingNosser]

http://www.3dmark.com/3dm11/7606860 @ stock

9k @950 core they didn't want to goto 1000mhz in SLI

The PSU done the job nicely it's really well made shame I couldn't plump for the full modular but it wasn't hard to make tidy with the cables, the braid on them is much better than many I've used and go a few inches into the PSU.

It also made a difference to my CPU scores in benches so is obviously putting in a lot better current than the old PSU, It's got a good chunk of weight to the thing slightly longer than a standard PSU.

Overall I'm happy enough now to wait it out until the 900 series cards which will most likely be a refresh of the maxwell series seems to be the trend atm.

If your in the market for a PSU thou your not go wrong with the XFX Pro series whichever option you decide.